Preliminary Study On Fermentation Technology, Colonization Dynamics In Field And Trial Of Disease-Control And Growth-Promotion By Bacillus Subtilis B2

The fermentation conditions of Baclillus subtilis B2 in fermentor and the methods of measurating whose quantity were studied elementarily, synchronously, its colonization dynamics around the rhizospheres of Angelica sinensis, Astragallus mongholicus and tomato and the disease prevention experiments for Angelica sinensis and potato in field were investigated. The results were as follows:1. The study on the fermentation technique of Baclillus subtilis B2Through the analysis of fermentation kinetic curves, the moderate fermentation time was 20h, through detecting the antifungal activity, the fiting harvest time was 36h,through othogonal test, the optimal match was inoculation rate 10%,pH 8.0 ventilation size 600L/h, rotate speed 200r/min.2. The study on the colonization dynamics of B2 around the rhizospheres of Angelica sinensis, Astragallus mongholicus and tomatoThe colonization variety trendency of B2 around the rhizospheres of Angelica sinensis, Astragallus mongholicus and tomato in this year was gently than that in last year, the active bacterial quantity of B2R on the root of Astragallus mongholicus reduced markly in the last coloning phase, finally, the order of magnitude went down nearly two, the active bacterial quantity of B2R around and on tomato fell remarkably, both went down two orders of magnitude, namely, the coloning abilities of B2R around the rhizospheres of Angelica sinensis and Astragallus mongholicus were strongly, while, the coloning ability around the rhizosphere of tomato was not very good.3. The prevention experiment of B2 for the root rot Angelica sinensisThe prevention effect of B2 for the root rot Angelica sinensis was 69.26%, which was distinctly higher than 52.56% of 20% Cupric acetate treatment, by treating Angelica sinensis with the twenty-fold liquid of number one bacterium screened newly, its yield increased 30.56%, the prevention effect reached to 82.60%.4. The prevention experiment of potato seed dressing with B2After dressing potato seed with B2, the potato diseases caused by Rhizoctonia spp and scab were controlled effectively, the yield of potato did not influenced makedly. By dressing potato seed with ten times liquid of B2, by contrast to the standard, the quantity of the fist and second class potatoes went up by 8.33% and6.25% respectively, meanwhile, Rhizoctonia spp and scab were restrained availably, by contrast to the standard ,the treatments went down by 17.71and 46.8 percentages.